交联阳离子淀粉的制备及其脱色性能

在碱催化剂6％氢氧化锂水溶液存在下,以N－（2,3－环氧丙基）三甲基氯化铵（GTA）为阳离子化试剂,制备了交联高取代度季铵型阳离子淀粉。考察了6％氢氧化锂水溶液、水含量、反应温度和反应时间对取代度和反应效率的影响。当淀粉用量为5．8g,GTA用量为3．0g时,最佳反应条件为：6％氢氧化锂水溶液2．0g、反应温度70℃、反应时间2h、反应体系含水量24．6％。在此条件下,取代度可达0．5,反应效率为83．3％。对制得阳离子淀粉的脱色性能研究结果表明,交联取代度阳离子淀粉对活性染料具有优异的脱色效果。当投加量为105mg/L时,对质量浓度为100mg/L活性红X－3B、活性黄KN－6G、活性蓝X－BR溶液的脱色率分别为99．1％、88．0％、95．5％。     

合成水杨酸-交联聚苯乙烯螯合树脂的新途径

采用氯甲基化试剂1,4-二氯甲氧基丁烷对交联聚苯乙烯(CPS)微球实施了氯甲基化反应,然后使5-氨基水杨酸(ASA)与氯甲基化交联聚苯乙烯微球表面的苄氯基团发生亲核取代反应,制得了氨基水杨酸-交联聚苯乙烯(ASA-CPS)螯合树脂.考察了主要反应条件对取代反应的影响,初步试验了ASA-CPS对金属离子的螯合性能.结果表明:ASA-CPS对Fe(Ⅲ)离子具有很强的螯合能力,吸附容量达3.77 mmol/g.     

N，N－二乙基二硫代氨基甲酸聚氯乙烯酯引发甲基丙烯酸甲酯的光接枝交联聚合反应

用铜试剂（Ｎ，Ｎ－二乙基二硫代氨基甲酸钠）取代聚氯乙烯中的部分氯原子制备了Ｎ，Ｎ－二乙基二硫代氨基甲酸聚氯乙烯酯（ＰＶＣ－ＳＲ），研究了紫外光照下ＰＶＣ－ＳＲ引发甲基丙烯酸甲酯（ＭＭＡ）的聚合反应，考察了光照时间、单体浓度、ＰＶＣ－ＳＲ用量及官能度的影响．结果表明，ＰＶＣ－ＳＲ能有效地引发ＭＭＡ聚合，其产物是交联型接枝聚合物，且具有高接枝率和接枝效率。     

两步后交联法制备氯甲基化聚苯乙烯交联微球

以平均粒径为40μm的非交联氯甲基化聚苯乙烯(CMPS)微球为出发物料,采用水解-轻度交联与重度交联两步骤的后交联方法,制备了氯甲基化聚苯乙烯交联微球.用红外光谱表征了交联前后微球化学结构的变化,使用扫描电镜观察了交联微球的形貌,重,点考察了各种交联条件对微球交联度的影响规律,分析了交联反应机理.结果表明:先将非交联氯甲基化聚苯乙烯微球部分水解并轻度交联,然后使CMPS微球在良溶剂中溶胀,使用Friedel-Crafts催化剂,再度进行交联反应,可顺利地制得氯甲基化聚苯乙烯(CCMPS)交联微球;控制交联反应的条件,如反应温度、反应时间、溶剂性质、催化剂种类与用量等,可获得交联度不同的微球,其球形度依然保持良好.     

Diels-Alder反应可控制备交联等规聚丙烯

交联改性可以提升聚合物材料的机械性能、热稳定性及化学稳定性。 含有蒽基团的高质均分子量等规聚丙烯(iPP)可由配位共聚合反应制得,随后通过双官能的马来酰亚胺试剂与iPP中悬挂蒽基团间的Diels-Alder反应可以成功制备交联的iPP膜材料。 材料的交联度可以通过凝胶重量分析及膜红外分析得出,并由制备过程中交联剂的加入量有效地调控。 通过示差扫描量热仪(DSC)与广角X射线衍射仪(WAXD)表征发现,随交联度增加,交联改性限制了分子链的运动,iPP的结晶度逐渐降低、结晶能力逐渐下降。 对交联材料的动态热机械分析仪(DMA)测试表明,随交联度增加,iPP的损耗模量逐渐降低,材料韧性变差。 交联iPP的T_g逐渐升高,说明材料的耐热性得到提升。 由于交联形成了聚合物链间的交联网络,形成了更多受力点并且限制了聚合物链的自由移动,交联材料的拉伸强度随交联度的升高而增加,而断裂伸长率逐渐下降。     

交联乙酰聚苯乙烯的合成及其膦化反应

交联聚苯乙烯在三氯化铝催化下与乙酸酐进行乙酰基化反应,得到交联聚苯乙烯乙酮树脂;研究了溶剂,温度,时间,试剂和催化剂用量对乙酰基化反应的影响。交联聚苯乙烯乙酮树脂进一步与三氯化磷作用,经冰醋酸处理,水解得到α-羟基膦酸树脂;溶剂,温度和时间对膦化反应均有影响。     

交联羧甲基红薯淀粉降低水中Ca~(2+)含量的研究

以环氧氯丙烷为交联剂,氯乙酸为羧甲基化试剂,合成交联羧甲基红薯淀粉并且研究其降低水中的Ca2+含量的效果.结果显示,交联羧甲基红薯淀粉吸附ca2+的适宜条件为,淀粉取代度0.721、2%淀粉用量、pH 8,吸附时间30min、吸附温度70℃下,交联羧甲基红薯淀粉对水中Ca2+的吸附量可达4.53mmol/L,Ca2+清除率为75.33%.交联羧甲基红薯淀粉吸附Ca2+的行为遵从Langmuir等温吸附方程.     

含Iniferter微凝胶及星型聚苯乙烯的合成

借助于超声波振荡分散法,通过苯乙烯-二乙烯基苯-对氯甲基苯乙烯三元共聚合反应合成了可溶性聚苯乙烯微凝胶,用二乙基二硫代氨基甲酸钠(铜试剂)取代其中的氯原子得到具有Iniferter功能的多官能度自由基活性微凝胶,该活性微凝胶引发苯乙烯聚合得到星型高分子,星型高分子中仍有Iniferter功能的基团.     

LDPE-AA两步法气相光接枝体系交联特征的研究

研究了以二苯甲酮为光引发剂 ,L DPE两步法气相光接枝丙稀酸反应体系的交联特征 ;考察了光照条件、反应温度及光引发剂含量对交联度的影响 ,发现并讨论了接枝反应对交联的促进作用 ,探讨了产生这种促进作用的机理。     

交联聚苯乙烯重氮盐的制备及其应用于偶合反应

通过大孔苯乙烯-二乙烯苯共聚体的硝化、还原和重氮化反应制得的交联聚苯乙烯重氮盐分别同取代酚(或芳香胺)羧酸或磺酸化合物(如水杨酸、对羟基苯甲酸、2,4-二羟基苯甲酸、没食子酸、2-羟基-3-羧基萘、磺基水杨酸、对氨基苯磺酸、4-羟基萘磺酸)和水杨醛等进行偶合反应制得了一类新型阳离子交换树脂。另外,还研究了反应介质的pH值和偶合试剂的结构等因素对偶合反应的影响。合成的离子交换树脂对铜离子和铁离子等有良好的选择性和对某些维生素和抗菌素有好的吸附-解吸性能。     

丙烯酰胺在以N,N-二乙基二硫代氨基甲酰基修饰聚氯乙烯上的紫外光非均相接枝聚合

丙烯酰胺在以Ｎ，Ｎ 二乙基二硫代氨基甲酰基修饰聚氯乙烯上的紫外光非均相接枝聚合杨文君王永祥管建均（青岛化工学院橡塑工程研究所青岛２６６０４２）沈家骢（吉林大学化学系长春１３００２３）关键词聚氯乙烯，聚丙烯酰胺，功能高分子，接枝聚合反应，铜试剂以聚氯...     

Highly reusable support‐free copper(II) complex of para‐hydroxy‐substituted salen: Novel,efficient and versatile catalyst for C─N bond forming reactions

An air‐stable, highly active and versatile method for C─N bond forming reactions is reported. Under mild conditions using a highly reusable support‐free Cu(II)–salen complex, structurally diverse N ‐aryl‐substituted compounds were obtained via direct C─N bond forming reaction of HN‐heterocycles with aryl iodides or three‐component C─N bond forming reaction of 2‐bromobenzaldehyde, aniline derivatives and sodium azide in good to excellent yields. C─N bond forming reaction for benzimidazole derivatives was also performed in the presence of the catalyst under ambient conditions. A series of hybrid benzimidazoles bearing morpholine, tetrazole and quinoxaline backbones were produced using this method. All reactions were performed in short times under air. The Cu(II) catalyst could be reused up to eight times in the direct cross‐coupling reaction of 9H –carbazole with iodobenzene without any decrease in its catalytic activity.     

Preparation and properties of macroporous superabsorbent composite

A fast swelling macroporous superabsorbent composite was prepared by the copolymerization of partially neutralized acrylic acid, 2‐acryloylamino‐2‐methyl‐1‐propanesulfonic acid (AMPS), and attapulgite (APT) using N, N′‐methylenebisacrylamide (NNMBA) and trihydroxymethyl propane glycidol ether as crosslinking agents. For fast swelling rate (SR), sodium bicarbonate, polyethylene glycol (PEG), and sodium carboxymethylcellulose (CMC) were introduced into the reaction system as foaming agent and stabilizers. Furthermore, the copolymer was surface‐crosslinked with glycerine and sodium silicate, and then blended with aluminum sulfate and sodium carbonate. The influences of the amount of NNMBA, trihydroxymethyl propane glycidol ether, PEG, CMC and sodium bicarbonate, and reaction temperature on water absorbence both under atmospheric pressure and load, and on the SR were investigated. The water absorbence of the sample in 0.9 wt% NaCl aqueous solution under atmospheric pressure and certain load (P ≈ 2 × 10³ Pa) could reach 54 and 8 g.g^?1, respectively, and the SR could reach 0.471 ml g^?1 s^?1. The excellent strength, resilience, and the dispersion of swollen hydrogel were also observed for the sample. Moreover, the surface morphology of macroporous superabsorbent composite was characterized using scanning electron microscope. Copyright © 2009 John Wiley & Sons, Ltd.     

聚氯乙烯的热可逆共价交联

利用环戊二烯 (CPD)在常温下自动二聚形成双环戊二烯 (DCPD)、在高温下DCPD又可解聚成CDD的热可逆Diels Alder反应 ,合成了DCPD二羧酸衍生物 ,并将其引作聚氯乙烯 (PVC)的共价交联 ,研究了交联剂种类和用量对交联程度、力学性能和流动特性的影响及交联产物的热可逆转化行为 ,制得了力学性能和耐热性均有所提高的热可逆共价交联PVC     

An Efficient Synthesis of Pyrazolyl‐1,2,3‐thiadiazoles via Hurd–Mori Reaction

An efficient synthetic strategy has been developed for the synthesis of pyrazolyl‐1,2,3‐thiadiazoles via Hurd–Mori cyclization reaction. The reaction of various pyrazolyl‐phenylethanones with semicarbazide hydrochloride in the presence of sodium acetate/methanol gave the corresponding semicarbazones ( 3a – i ). These semicarbazones were further reacted with thionyl chloride via the Hurd–Mori cyclization conditions to accomplish the title products ( 4a – i ). The present protocol favored for the formation of both pyrazolyl semicarbazone derivatives and pyrazolyl‐1,2,3‐thiadiazole derivatives by forming C─S, N─S, and C═N bonds in excellent yields with variety of substrates. The final compounds were characterized by analytical and spectral studies.     

增塑化学微交联聚氯乙烯中化学交联和物理交联的协同作用

由氯乙烯／ 邻苯二甲酸二烯丙基酯（ＶＣ／ＤＡＰ） 悬浮共聚合成了化学微交联聚氯乙烯（ＰＶＣ） 树脂,并进行增塑加工．共聚得到的化学交联ＰＶＣ 具有溶胶／ 凝胶分配特性,交联密度较低;化学交联ＰＶＣ 的溶胶和凝胶均存在分子链缠结作用,尤其当凝胶含量较高时,物理缠结对凝胶交联密度有较大贡献．化学交联对增塑ＰＶＣ 结晶性的影响较小,因此在增塑化学微交联ＰＶＣ 中同时存在化学交联网络和以分子链物理缠结点和微晶为交联点的物理交联网络,两者协同影响增塑ＰＶＣ 材料的性能．     

Merrifield-like resin beads by acid catalyzed incorporation of benzyl chloride into dehydrochlorinated PVC

A method is presented for preparing Merrifield-like resin beads starting from poly (vinyl chloride) (PVC) in spherical bead form. In this method, first, PVC is partially dehydrochlorinated in boiling methanolic KOH (20%) solution to create minute amounts of allylic carbon centers. Those centers trigger the un-zipping process and make further dehydrochlorination possible at relatively low temperatures (180-200 °C), while retaining the bead shapes. Acid catalyzed reaction of the dehydrochlorinated PVC particles with benzyl chloride at 180 °C yields crosslinked spherical bead polymers possessing chloromethyl benzene functions as high as 3.4 mmol g⁻¹. Experiments showed that, high yields of benzyl chloride insertions can be attained by using PVC samples with 40-50% of unsaturations. In the study transformation yields in each step were followed by conventional analytical methods and IR spectrometry. It was also demonstrated that modification of the chloromethyl groups either with KCN or sodium acetate proceeds with nearly quantitative yields, as in the case for chloromethylated styrene-divinyl benzene resins.     

Modification of poly(vinyl chloride). X. Crosslinking of poly(vinyl chloride) with a soft segment of an elastomer containing thiol groups

To obtain poly(vinyl chloride) (PVC) of excellent toughness, a new method of crosslinking PVC is proposed in which PVC is crosslinked with the soft segment in an elastomer such as liquid Thiokol. The reaction can be accomplished by immersing PVC–Thiokol blends in liquid ammonia at 20–30°C. A similar reaction occurs in aqueous ammonia when hexamethylphosphoramide is used as an activator. Characteristics of the crosslinked PVC thus obtained and of the controls of a similar uncrosslinked composition (PVC–Thiokol LP-8, 100:5 by weight) were as follows: tensile strength, 7.3 and 4.8 kg/mm²; elongation at break, 30 and 2.5%; Young's modulus, 3.5 × 10⁴ and 2.9 × 10⁴ kg/cm²; tensile impact, 88 and 15 kg-cm/cm³, respectively. The crosslinked PVC as plasticized with dioctyl phthalate (DOP) and the control blend (PVC–Thiokol LP-8–DOP, 100:10:10 by weight), respectively, showed tensile strengths of 5.9 and 4.8 kg/mm², elongations at break of 44 and 24%, Young's moduli of 2.5 × 10⁴ and 1.6 × 10⁴ kg/cm², and tensile impact strengths of 62 and 120 kg-cm/cm³. As the crosslinkage through the soft segments increases up to about 5%, the elongation at break, Young's modulus, and tensile impact, in addition to the tensile strength, are improved. This is different from the results so far observed with the crosslinked amorphous polymers and is characteristic of the products of crosslinking through the soft segment. The experimental results are discussed in this paper.     

互贯型螯合树脂的研究(Ⅰ)─交联聚苯乙烯－聚丙烯腈互贯树脂的合成

研究了交联聚苯乙烯-聚丙烯腈新型互贯树脂(PS-PAN)的合成,考察了交联度、重量比、孔结构和溶剂对互贯量的影响。结果表明,以凝胶型树脂为第一网时,交联度的影响比较显着,两网交联度相同时互贯量最大;以大孔型树脂做第一网时,孔结构的作用较突出。此外,溶剂对互贯量的影响非常大。